Ignoring life expectancy can lead to poor clinical decisions. Healthy older adults who could benefit from screening have low screening rates. Older adults with dementia or metastatic cancer are screened for slow- growing cancers that are unlikely to cause symptoms but may lead to distress from false-positive results, invasive work-ups and treatments. Life expectancy calculators offer the possibility of moving beyond arbitrary age-based cutoffs to more rational life expectancy based decision-making, incorporating age as well as other factors known to predict mortality such as comorbidities, demographics, laboratory results and pharmacy data. The objectives of the study are to (a) develop and validate a 10-year life expectancy calculator using 2005 VA electronic data (demographics, comorbidities, laboratory results and pharmacy records); (b) develop and validate an Augmented life expectancy calculator that adds 2009 functional assessments (Activities of Daily Living or ADL and Instrumental Activities of Daily Living or IADL assessments) to the other risk factors and determine whether the addition of ADL and IADL data lead to improved discrimination; ); (c) develop and validate a VA-Medicare life expectancy calculator that adds 2009 Medicare data to the other risk factors and determine whether the addition of Medicare data lead to improved discrimination; (d) apply the life expectancy calculator to a national VA cohort to determine the proportion of colorectal cancer (CRC) screening that occurs in veterans with limited life expectancy (<25% likelihood of life expectancy of 10+ years) and extended life expectancy (>75% likelihood of life expectancy of 10+ years) in both veterans within the recommended age (50-75) for CRC screening as well as veterans at more advanced age (76-85) when screening is not routinely recommended. By developing and validating a VA electronic data driven life expectancy calculator, this project will determine the rates of potentially inappropriate CRC overscreening in age-appropriate veterans (age 50-75) with a limited life expectancy (<25% likelihood of life expectancy 10+ years). Conversely, this project will also identify potentially inappropriate CRC underscreening in veterans beyond the recommend age for screening (age 76-85) with an extended life expectancy (>75% likelihood of life expectancy of 10+ years). This work will provide the critical foundation for an intervention to improve the targeting of CRC screening will estimate an individual veterans' life expectancy to 1) suppress CRC screening clinical reminders for patients with limited life expectancy (age 50-75) or 2) trigger CRC screening clinical reminders for patients with extended life expectancy (age 76-85). Further, accurate life expectancy estimates could also be utilized to individualize other prevention decisions that have a long time to benefit, such as breast cancer screening and intensive glycemic control. Thus, this work would be another way that the VA would become a Learning Healthcare System that uses clinical data to individualize veterans' prevention decisions and inform system-wide decisions regarding prevention clinical alerts.